Don't record slots of objects that may contain raw values.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index ea3b008a98b882634a65412c28ec92bafa1557bb..21f46265b8b412d96d417e34f0a00680da4ceb0a 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1473,21 +1473,21 @@ int HeapObject::Size() {
 }
 
 
-bool HeapObject::MayContainNewSpacePointers() {
+bool HeapObject::MayContainRawValues() {
   InstanceType type = map()->instance_type();
   if (type <= LAST_NAME_TYPE) {
     if (type == SYMBOL_TYPE) {
-      return true;
+      return false;
     }
     DCHECK(type < FIRST_NONSTRING_TYPE);
     // There are four string representations: sequential strings, external
     // strings, cons strings, and sliced strings.
     // Only the latter two contain non-map-word pointers to heap objects.

[Michael Starzinger, 2014/09/09 10:00:08]

nit: s/the latter two contain non-map-word pointers to heap objects/the former
two contain raw values and no heap pointers (besides the map-word)/

[Hannes Payer (out of office), 2014/09/09 10:05:16]

Done.

-    return ((type & kIsIndirectStringMask) == kIsIndirectStringTag);
+    return ((type & kIsIndirectStringMask) != kIsIndirectStringTag);
   }
   // The ConstantPoolArray contains heap pointers, but not new space pointers.

[Michael Starzinger, 2014/09/09 10:00:08]

nit: s/but not new space pointers/but also raw values/

[Hannes Payer (out of office), 2014/09/09 10:05:16]

Done.

-  if (type == CONSTANT_POOL_ARRAY_TYPE) return false;
-  return (type > LAST_DATA_TYPE);
+  if (type == CONSTANT_POOL_ARRAY_TYPE) return true;
+  return (type <= LAST_DATA_TYPE);
 }